The present invention relates to an apparatus for externally grasping spun yarn carriers in spinning machines or twisting machines and, more particularly, to grasping apparatus equipped with a movable clamping arrangement and a stationary clamping arrangement whose clamping surfaces are oriented with respect to the axis of a machine spindle or pin for receiving the spun yarn carrier.
A cop removal device is known from German Patent Publication DE-AS 24 42 222 in which a stationary clamping element consists of a ring whose diameter is greater than the diameter of the cop tube to be removed. A piston with a frontally arranged clamping surface is movable radially in the direction of the axis of the ring to form an adjustable clamping element. In the operating position, the ring is guided over the cop until the desired clamping position has been reached. The cop is subsequently clamped by means of moving the piston between its clamping surface and the inner side of the ring located opposite the piston.
German Patent Publication DE-OS 36 40 002 teaches a disk-shaped grasping device with two integrated grasping elements. Each grasping element is provided with a vertical recess configured to be approximately circular for receiving a yarn carrier and on whose circumference two stationary clamping elements staggered by 120.degree. are located. A movable clamping element which constitutes a component of a pneumatically adjustable piston is associated with the stationary clamping elements and has a clamping surface staggered by a further 120.degree. spacing therefrom. When the spun yarn carrier is grasped, the movable clamping element is moved in the direction of the spun yarn carrier located in the recess and this carrier is clamped between the stationary clamping elements and the clamping surface of the movable clamping element.